Kaiser Fung points to the above self-canceling statement which comes from a quantitatively-trained expert on international debt. I can only assume that he was speaking quickly and that the reporter didn’t know enough to ask him to clarify. When I’m interviewed, I emit a lot of ums, uhs, and probably quite a few meaningless remarks, but usually whoever is interviewing me knows to just keep the good stuff. As Kaiser points out, the above quote could mean two completely opposite things! In context I’m sure it was clear to the speaker but it’s not at all obvious what’s going on in the published version. Again, I’m not blaming the expert here, it’s just a miscommunication that got into the article, something that Kaiser noticed (and that I care about) because of our interest in probability communication.
In any case, the line “at least as much as an 80 percent chance” should join “But viewed in retrospect, it is clear that it has been quite predictable” in the Probability Hall of Fame.
P.S. I was curious about the background of Kenneth Rogoff (the source of the above quote) so I looked him up and found this mini-autobiography, which for some reason irritated me. I’m not sure if it was the odd line about his parents being “true liberals” or the exhaustive detail about the various newspapers and books that reprinted his old chess games. I can’t fault the guy for bragging—in some ways, this entire blog is a big brag—but there was something about the tone of Rogoff’s bragging that put me off. My favorite part was where he mentions that he finished 13th in a chess tournament in 1976—he is oddly precise and lists his place as “tied for 13th-15th”—but qualifies this by explaining that he played only in the summers, unlike the other players who were full-time professionals. I have to admit, if I’d ever been good enough in a sport to finish 13th in a major tournament, I’d probably find a way to work it onto my webpage too.